1. Field of the Invention
The present invention relates to a communication device and method, especially to a communication device and method applicable to a stacking communication system.
2. Description of Related Art
In a relative large-scale network topology, stacking technology is helpful to the connection of a plurality of physical network devices (e.g., a plurality of switches) for the accomplishment of a logical stacking network device (hereafter, stacking network system). Such stacking network system is superior to a single physical network device in forwarding efficiency and capability. Stacking technology allows a user to manage all of the physical network devices in a stacking network system and increases the overall packet forwarding capability of the stacking network system.
Regarding the current stacking technology, if two devices in a stacking network system intend to access resources from each other, the upper-layer application software of the two devices will carry out mutual communication through a standard Ethernet network frame and a known network communication protocol, in which the format of the standard Ethernet network frame must comply with a given specification and the length of the frame must be equal to or greater than 64 bytes so as to prevent the frame from being discarded as an invalid frame by a reception end. Accordingly, the said upper-layer application software has to include a complete communication protocol layer, which leads to the complexity of the mutual communication in practice. Besides, in order to prevent the generation of a network loop caused by the nonstop transmission of a frame among devices, some stacking technology will make use of a spanning tree protocol (STP) to set up a network break node. The STP is capable of converting a complicated topology into a tree configuration in logic and configuring the port(s) of each device in a stacking system to make the port(s) block or forward a frame, so as to prevent the generation of a network loop; however, this process will consume a lot of calculation resources. People who are interested in the STP may refer to IEEE 802.1 standard(s) (e.g., 802.1Q standard, 802.1D standard, etc.).